CLEANUP: Fix typo in the 51d subsystem

Fixes a typo in the code comments of the 51d subsystem.
diff --git a/src/51d.c b/src/51d.c
index 2a97867..4f49421 100644
--- a/src/51d.c
+++ b/src/51d.c
@@ -380,7 +380,7 @@
 	struct lru64 *lru = NULL;
 #endif
 
-	/* Needed to ensure that the HTTP message has been fully recieved when
+	/* Needed to ensure that the HTTP message has been fully received when
 	 * used with TCP operation. Not required for HTTP operation.
 	 * Data type has to be reset to ensure the string output is processed
 	 * correctly.