compositor: add fallback strchrnul()

Android does not have this function.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

shared/os-compatibility.c

@@ -168,3 +168,13 @@ os_create_anonymous_file(off_t size)
 
 	return fd;
 }
+
+#ifndef HAVE_STRCHRNUL
+char *
+strchrnul(const char *s, int c)
+{
+	while (*s && *s != c)
+		s++;
+	return (char *)s;
+}
+#endif

shared/os-compatibility.h

@@ -46,4 +46,9 @@ os_epoll_create_cloexec(void);
 int
 os_create_anonymous_file(off_t size);
 
+#ifndef HAVE_STRCHRNUL
+char *
+strchrnul(const char *s, int c);
+#endif
+
 #endif /* OS_COMPATIBILITY_H */