qcacld-3.0: Release sme global lock in the error condition

with recent commit 203218df88e7 
("qcacld-3.0: Set sme power stats response cb and context to NULL")  
fix in the error condition the sme global lock is not getting released 
resulting in the mc thread being struck.

Release the sme global lock in the error condition.

Change-Id: I6235a632c6b74c48374d4584eb727bf9ffe296a8
CRs-Fixed: 2867358

core/sme/src/common/sme_api.c

@@ -10250,6 +10250,7 @@ QDF_STATUS sme_power_debug_stats_req(
 		if (mac_ctx->sme.power_debug_stats_context ||
 		    mac_ctx->sme.power_stats_resp_callback) {
 			sme_err("Already one power stats req in progress");
+			sme_release_global_lock(&mac_ctx->sme);
 			return QDF_STATUS_E_ALREADY;
 		}
 		mac_ctx->sme.power_debug_stats_context = power_stats_context;