Fix a couple of comment typos

Author: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/CAEG8a3+MRwDKc4YSFKKPKq7Y+vMufVC5u94wM5KZPB2CbgCxnQ@mail.gmail.com

src/backend/access/transam/multixact.c

@@ -1287,7 +1287,7 @@ GetNewMultiXactId(int nmembers, MultiXactOffset *offset)
  * range, in which case an error would be raised.
  *
  * In all other cases, the passed multixact must be within the known valid
- * range, that is, greater to or equal than oldestMultiXactId, and less than
+ * range, that is, greater than or equal to oldestMultiXactId, and less than
  * nextMXact.  Otherwise, an error is raised.
  *
  * isLockOnly must be set to true if caller is certain that the given multi

src/backend/utils/adt/jsonfuncs.c

@@ -1723,7 +1723,7 @@ push_path(JsonbParseState **st, int level, Datum *path_elems,
 {
 	/*
 	 * tpath contains expected type of an empty jsonb created at each level
-	 * higher or equal than the current one, either jbvObject or jbvArray.
+	 * higher or equal to the current one, either jbvObject or jbvArray.
 	 * Since it contains only information about path slice from level to the
 	 * end, the access index must be normalized by level.
 	 */