msm: ipc: Update recvmsg operation to be non-blocking by default

Update the IPC Router recvmsg operation to be non-blocking by default
and return 0 when there is no data to read.

CRs-Fixed: 464634
Change-Id: I1f43e3a36d72312372a3ac141d506c81a613c408
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
diff --git a/arch/arm/mach-msm/ipc_socket.c b/arch/arm/mach-msm/ipc_socket.c
index cb1bc7a..e6c490e 100644
--- a/arch/arm/mach-msm/ipc_socket.c
+++ b/arch/arm/mach-msm/ipc_socket.c
@@ -415,7 +415,7 @@
 		}
 
 		if (timeout == 0)
-			return -ETIMEDOUT;
+			return 0;
 		lock_sock(sk);
 		mutex_lock(&port_ptr->port_rx_q_lock);
 	}