CLEANUP: cfgparse: Remove unused label end

This removes the end label from parse_process_number() which
is unused since 5ab51775e736511b7e54f42e080dcef76a284da9, which
first was released in haproxy 1.8.0.
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 40facd5..27d7eee 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -662,7 +662,6 @@
 			*proc |= 1UL << (low-1);
 	}
 
-  end:
 	return 0;
 }