net: qrtr: Revert lock sock changes in qrtr_recvmsg

lock_sock got wrongly added in qrtr_recvmsg as part of the
patch "net: qrtr: print error case for qrtr receive".
Reverting lock_sock and release_sock in qrtr_recvmsg.

Change-Id: I7f9639405a67e2201a848277145bac57c88f6567
Signed-off-by: Sarannya S <sarannya@codeaurora.org>