Fix coverity CID 143502: Null pointer dereference

* libc/locale/ldpart.c (split_lines): Don't dereference result
	of strchr without checking for NULL pointer first.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

newlib/libc/locale/ldpart.c

@@ -175,6 +175,8 @@ split_lines(char *p, const char *plim) {
 
 	for (i = 0; p < plim; i++) {
 		p = strchr(p, '\n');
+		if (!p)
+			break;
 		*p++ = '\0';
 	}
 	return i;