RT3547: Add missing static qualifier

Reviewed-by: Ben Laurie <ben@openssl.org>
(cherry picked from commit 87d388c9)

crypto/constant_time_locl.h

@@ -204,7 +204,7 @@ static inline unsigned char constant_time_select_8(unsigned char mask,
 	return (unsigned char)(constant_time_select(mask, a, b));
 	}
 
-inline int constant_time_select_int(unsigned int mask, int a, int b)
+static inline int constant_time_select_int(unsigned int mask, int a, int b)
 	{
 	return (int)(constant_time_select(mask, (unsigned)(a), (unsigned)(b)));
 	}