net: dsa: Fix spelling mistakes and cleanup code

fix follow spelling misktakes:
desconstructed ==> deconstructed
enforcment ==> enforcement

Reported-by: Hacash Robot <[e-mail]>
Signed-off-by: Xie Shaowen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/dsa/tag_brcm.c

···
 /* Newer Broadcom tag (4 bytes) */
 #define BRCM_TAG_LEN	4
 
-/* Tag is constructed and desconstructed using byte by byte access
+/* Tag is constructed and deconstructed using byte by byte access
  * because the tag is placed after the MAC Source Address, which does
  * not make it 4-bytes aligned, so this might cause unaligned accesses
  * on most systems where this is used.
···
 
 	brcm_tag = skb->data + offset;
 
-	/* Set the ingress opcode, traffic class, tag enforcment is
+	/* Set the ingress opcode, traffic class, tag enforcement is
 	 * deprecated
 	 */
 	brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |