refspec: trivial cleanup

We can remove one level of indentation and make the code clearer.

No functional changes.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refspec.c

@@ -272,7 +272,9 @@ void refspec_ref_prefixes(const struct refspec *rs,
 		else if (item->src && !item->exact_sha1)
 			prefix = item->src;
 
-		if (prefix) {
+		if (!prefix)
+			continue;
+
 		if (item->pattern) {
 			const char *glob = strchr(prefix, '*');
 			strvec_pushf(ref_prefixes, "%.*s",
@@ -282,5 +284,4 @@ void refspec_ref_prefixes(const struct refspec *rs,
 			expand_ref_prefix(ref_prefixes, prefix);
 		}
 	}
-	}
 }