Update src/credentials/CHIPCert.h

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

src/credentials/CHIPCert.h

@@ -792,7 +792,7 @@ CHIP_ERROR ExtractFabricIdFromCert(const ChipCertificateData & cert, FabricId *
  *
  * @return CHIP_ERROR_NOT_FOUND if the passed-in cert does not have at
  * least one NodeId RDN and one FabricId RDN in the Subject DN.  No other
- * validation (e.g. checkign that there is exactly one RDN of each type) is
+ * validation (e.g. checking that there is exactly one RDN of each type) is
  * performed.
  */
 CHIP_ERROR ExtractNodeIdFabricIdFromOpCert(const ChipCertificateData & opcert, NodeId * nodeId, FabricId * fabricId);