s/master/main/

Test: treehugger
Change-Id: I2c975b2f5f92f23c7357b6f7e785578504298cc6
diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index 6f992d9..d22b85c 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -361,7 +361,7 @@
  *
  * Available since API level 28.
  *
- * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/master/libc/malloc_hooks/README.md)
+ * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/main/libc/malloc_hooks/README.md)
  */
 extern void* _Nonnull (*volatile _Nonnull __malloc_hook)(size_t __byte_count, const void* _Nonnull __caller) __INTRODUCED_IN(28);
 
@@ -372,7 +372,7 @@
  *
  * Available since API level 28.
  *
- * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/master/libc/malloc_hooks/README.md)
+ * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/main/libc/malloc_hooks/README.md)
  */
 extern void* _Nonnull (*volatile _Nonnull __realloc_hook)(void* _Nullable __ptr, size_t __byte_count, const void* _Nonnull __caller) __INTRODUCED_IN(28);
 
@@ -383,7 +383,7 @@
  *
  * Available since API level 28.
  *
- * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/master/libc/malloc_hooks/README.md)
+ * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/main/libc/malloc_hooks/README.md)
  */
 extern void (*volatile _Nonnull __free_hook)(void* _Nullable __ptr, const void* _Nonnull __caller) __INTRODUCED_IN(28);
 
@@ -394,7 +394,7 @@
  *
  * Available since API level 28.
  *
- * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/master/libc/malloc_hooks/README.md)
+ * See also: [extra documentation](https://android.googlesource.com/platform/bionic/+/main/libc/malloc_hooks/README.md)
  */
 extern void* _Nonnull (*volatile _Nonnull __memalign_hook)(size_t __alignment, size_t __byte_count, const void* _Nonnull __caller) __INTRODUCED_IN(28);