builtin-apply: remove unused increment

We do not use desc.alloc after assigning desc.buffer to patch->result;
do not bother to increment it.

Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-apply.c b/builtin-apply.c
index c159873..be2c715 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -1700,10 +1700,8 @@
 		return -1;
 
 	/* NUL terminate the result */
-	if (desc.alloc <= desc.size) {
+	if (desc.alloc <= desc.size)
 		desc.buffer = xrealloc(desc.buffer, desc.size + 1);
-		desc.alloc++;
-	}
 	desc.buffer[desc.size] = 0;
 
 	patch->result = desc.buffer;