net: fddi: skfp: ecm: Protect 'if' when AIX_EVENT is not defined

When AIX_EVENT is not defined, the 'if' body will be empty, which
makes GCC complain.  Place bracketing around the invocation to protect
it.

Fixes the following W=1 kernel build warning(s):

 drivers/net/fddi/skfp/ecm.c: In function ‘ecm_fsm’:
 drivers/net/fddi/skfp/ecm.c:153:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201102114512.1062724-2-lee.jones@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/fddi/skfp/ecm.c

@@ -147,10 +147,11 @@ static void ecm_fsm(struct s_smc *smc, int cmd)
 	/* For AIX event notification: */
 	/* Is a disconnect  command remotely issued ? */
 	if (cmd == EC_DISCONNECT &&
-		smc->mib.fddiSMTRemoteDisconnectFlag == TRUE)
+	    smc->mib.fddiSMTRemoteDisconnectFlag == TRUE) {
 		AIX_EVENT (smc, (u_long) CIO_HARD_FAIL, (u_long)
 			FDDI_REMOTE_DISCONNECT, smt_get_event_word(smc),
 			smt_get_error_word(smc) );
+	}
 
 	/*jd 05-Aug-1999 Bug #10419 "Port Disconnect fails at Dup MAc Cond."*/
 	if (cmd == EC_CONNECT) {