Prefer __nodiscard to __wur for readability.

[[nodiscard]] is the C++17 and C23 spelling, and even if you're not familiar with that yet, "wur" doesn't mean anything to anyone who isn't a libc maintainer!

Change-Id: I9a63b1e438a347a56535b01d6d05532ee052bcea
diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index 77b5b02..2fa4b49 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -55,7 +55,7 @@
  * other processes. Obviously this is not the case for apps, which will
  * be killed in preference to killing other processes.
  */
-__wur void* _Nullable malloc(size_t __byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(1);
+__nodiscard void* _Nullable malloc(size_t __byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(1);
 
 /**
  * [calloc(3)](https://man7.org/linux/man-pages/man3/calloc.3.html) allocates
@@ -64,7 +64,7 @@
  * Returns a pointer to the allocated memory on success and returns a null
  * pointer and sets `errno` on failure (but see the notes for malloc()).
  */
-__wur void* _Nullable calloc(size_t __item_count, size_t __item_size) __mallocfunc __BIONIC_ALLOC_SIZE(1,2);
+__nodiscard void* _Nullable calloc(size_t __item_count, size_t __item_size) __mallocfunc __BIONIC_ALLOC_SIZE(1,2);
 
 /**
  * [realloc(3)](https://man7.org/linux/man-pages/man3/realloc.3.html) resizes
@@ -74,7 +74,7 @@
  * memory on success and returns a null pointer and sets `errno` on failure
  * (but see the notes for malloc()).
  */
-__wur void* _Nullable realloc(void* _Nullable __ptr, size_t __byte_count) __BIONIC_ALLOC_SIZE(2);
+__nodiscard void* _Nullable realloc(void* _Nullable __ptr, size_t __byte_count) __BIONIC_ALLOC_SIZE(2);
 
 /**
  * [reallocarray(3)](https://man7.org/linux/man-pages/man3/realloc.3.html) resizes
@@ -88,10 +88,10 @@
  * (but see the notes for malloc()).
  */
 #if __ANDROID_API__ >= 29
-__wur void* _Nullable reallocarray(void* _Nullable __ptr, size_t __item_count, size_t __item_size) __BIONIC_ALLOC_SIZE(2, 3) __INTRODUCED_IN(29);
+__nodiscard void* _Nullable reallocarray(void* _Nullable __ptr, size_t __item_count, size_t __item_size) __BIONIC_ALLOC_SIZE(2, 3) __INTRODUCED_IN(29);
 #else
 #include <errno.h>
-static __inline __wur void* _Nullable reallocarray(void* _Nullable __ptr, size_t __item_count, size_t __item_size) {
+static __inline __nodiscard void* _Nullable reallocarray(void* _Nullable __ptr, size_t __item_count, size_t __item_size) {
   size_t __new_size;
   if (__builtin_mul_overflow(__item_count, __item_size, &__new_size)) {
     errno = ENOMEM;
@@ -116,13 +116,13 @@
  *
  * See also posix_memalign().
  */
-__wur void* _Nullable memalign(size_t __alignment, size_t __byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(2);
+__nodiscard void* _Nullable memalign(size_t __alignment, size_t __byte_count) __mallocfunc __BIONIC_ALLOC_SIZE(2);
 
 /**
  * [malloc_usable_size(3)](https://man7.org/linux/man-pages/man3/malloc_usable_size.3.html)
  * returns the actual size of the given heap block.
  */
-__wur size_t malloc_usable_size(const void* _Nullable __ptr);
+__nodiscard size_t malloc_usable_size(const void* _Nullable __ptr);
 
 #define __MALLINFO_BODY \
   /** Total number of non-mmapped bytes currently allocated from OS. */ \