Fix typos in e0b1ee17dc

Reported-by: Alexander Lakhin

src/backend/access/nbtree/nbtsearch.c

@@ -1665,7 +1665,7 @@ _bt_readpage(IndexScanDesc scan, ScanDirection dir, OffsetNumber offnum)
 			/*
 			 * If the result of prechecking required keys was true, then in
 			 * assert-enabled builds we also recheck that _bt_checkkeys()
-			 * result is is the same.
+			 * result is the same.
 			 */
 			Assert(!requiredMatchedByPrecheck ||
 				   passes_quals == _bt_checkkeys(scan, itup, indnatts, dir,

src/backend/access/nbtree/nbtutils.c

@@ -1415,7 +1415,7 @@ _bt_checkkeys(IndexScanDesc scan, IndexTuple tuple, int tupnatts,
 
 		/*
 		 * Is the key required for scanning for either forward or backward
-		 * direction?  If so and called told us that these types of keys are
+		 * direction?  If so and caller told us that these types of keys are
 		 * known to be matched, skip the check.  Except for the row keys,
 		 * where NULLs could be found in the middle of matching values.
 		 */