qcacld-3.0: sap: Replace fallthrough comment with attribute

-Wimplicit-fallthrough is being enabled by default. Some compilers
such as clang require the attribute instead of just a fallthrough comment.

Change-Id: I34248b07875ea4b615be84aba26798f10e7773ec
CRs-Fixed: 3217419

core/sap/src/sap_module.c

@@ -2326,7 +2326,7 @@ wlansap_reset_sap_config_add_ie(struct sap_config *config,
 		}
 		if (eUPDATE_IE_ALL != updateType)
 			break;
-		/* fallthrough */
+		fallthrough;
 	case eUPDATE_IE_ASSOC_RESP:
 		if (config->pAssocRespIEsBuffer) {
 			qdf_mem_free(config->pAssocRespIEsBuffer);
@@ -2335,7 +2335,7 @@ wlansap_reset_sap_config_add_ie(struct sap_config *config,
 		}
 		if (eUPDATE_IE_ALL != updateType)
 			break;
-		/* fallthrough */
+		fallthrough;
 	case eUPDATE_IE_PROBE_BCN:
 		if (config->pProbeRespBcnIEsBuffer) {
 			qdf_mem_free(config->pProbeRespBcnIEsBuffer);
@@ -2344,7 +2344,7 @@ wlansap_reset_sap_config_add_ie(struct sap_config *config,
 		}
 		if (eUPDATE_IE_ALL != updateType)
 			break;
-		/* fallthrough */
+		fallthrough;
 	default:
 		if (eUPDATE_IE_ALL != updateType)
 			sap_err("Invalid buffer type %d", updateType);