Use inline keyword without underscores consistently

s/__inline__/inline
s/__inline/inline

Change-Id: I5d8d930a7a41d678a0795e7a608dacbb9eb8cb37
diff --git a/libc/include/android/legacy_threads_inlines.h b/libc/include/android/legacy_threads_inlines.h
index c614cd0..06e7438 100644
--- a/libc/include/android/legacy_threads_inlines.h
+++ b/libc/include/android/legacy_threads_inlines.h
@@ -32,7 +32,7 @@
 
 #if __ANDROID_API__ < 30
 
-#define __BIONIC_THREADS_INLINE static __inline
+#define __BIONIC_THREADS_INLINE static inline
 #include <bits/threads_inlines.h>
 
 #endif