newlib: sys/unistd.h: Change inline to __inline

Addresses: https://sourceware.org/pipermail/cygwin-patches/2025q2/013644.html
Fixes: 3e8a7eb ("sys/unistd.h: fix definition of setproctitle_init")
Reported-by: Brian Inglis <[email protected]>
Co-authored-by: Corinna Vinschen <[email protected]>
Signed-off-by: Takashi Yano <[email protected]>
(cherry picked from commit 1c530c3)

Author: tyan0

newlib/libc/include/sys/unistd.h

@@ -215,7 +215,7 @@ int     setpgrp (void);
 #if defined(__CYGWIN__) && __BSD_VISIBLE
 /* Stub for Linux libbsd compatibility. */
 #define initsetproctitle(c, a, e) setproctitle_init((c), (a), (e))
-static inline void setproctitle_init (int _c, char *_a[], char *_e[]) {}
+static __inline void setproctitle_init (int _c, char *_a[], char *_e[]) {}
 
 void setproctitle (const char *, ...)
 		   _ATTRIBUTE ((__format__ (__printf__, 1, 2)));