Add missing nothrow attribute

The upcoming compiler update emits warning about the missing nothrow
attribute:

  bionic/libc/bionic/jemalloc.h:33:5: error: 'je_mallctl' is missing exception specification '__attribute__((nothrow))' [-Werror,-Wmissing-exception-spec]
  int je_mallctl(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen);
      ^
                                                                                           __attribute__((nothrow))
  external/jemalloc_new/include/jemalloc/jemalloc.h:230:38: note: previous declaration is here
  JEMALLOC_EXPORT int JEMALLOC_NOTHROW    je_mallctl(const char *name,
                                          ^
  external/jemalloc_new/include/jemalloc/jemalloc_rename.h:12:22: note: expanded from macro 'je_mallctl'
  #  define je_mallctl je_mallctl

Test: build with clang r365631
Bug: 131328001
Change-Id: Ia8b6f47d38e5a003b6282f10724b65b1f971ba84
diff --git a/libc/bionic/jemalloc.h b/libc/bionic/jemalloc.h
index b9a4e99..ef77c9c 100644
--- a/libc/bionic/jemalloc.h
+++ b/libc/bionic/jemalloc.h
@@ -30,7 +30,7 @@
 
 void* je_aligned_alloc_wrapper(size_t, size_t);
 int je_iterate(uintptr_t, size_t, void (*)(uintptr_t, size_t, void*), void*);
-int je_mallctl(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen);
+int je_mallctl(const char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen) __attribute__((nothrow));
 struct mallinfo je_mallinfo();
 void je_malloc_disable();
 void je_malloc_enable();