qcacmn: Remove an obsolete lock in host to target layer

After gerrit#2176826, which the change ID is
I615f0e4d6de150924b99b3444cebf00571ddc088, HTCCreditLock is
removed from creation. However, the destroy of this lock is
missed. Need to remove this obsolete lock completely.

CRs-Fixed: 2345978
Change-Id: I4b67aa2a12befcd94a04a8a6acd43e31ae0b837f

htc/htc_internal.h

@@ -190,7 +190,6 @@ typedef struct _HTC_TARGET {
 	qdf_spinlock_t HTCLock;
 	qdf_spinlock_t HTCRxLock;
 	qdf_spinlock_t HTCTxLock;
-	qdf_spinlock_t HTCCreditLock;
 	uint32_t HTCStateFlags;
 	void *host_handle;
 	struct htc_init_info HTCInitInfo;