Tegra: bpmp_ipc: improve cyclomatic complexity

Code complexity is a good indication of maintainability versus
testability of a piece of software.

ISO26262 introduces the following thresholds:

    complexity < 10 is accepted
    10 <= complexity < 20 has to be justified
    complexity >= 20 cannot be accepted

Rationale is that number of test cases to fully test a piece of
software can (depending on the coverage metrics) grow exponentially
with the number of branches in the software.

This patch removes redundant conditionals from 'ipc_send_req_atomic'
handler to reduce the McCabe Cyclomatic Complexity for this function

Change-Id: I20fef79a771301e1c824aea72a45ff83f97591d5
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/drivers/bpmp_ipc/intf.c

@@ -175,11 +175,9 @@ static int32_t tegra_bpmp_ipc_send_req_atomic(uint32_t mrq, void *p_out,
 	if ((p_out == NULL) || (size_out > IVC_DATA_SZ_BYTES) ||
 	    (frame == NULL)) {
 		ERROR("%s: invalid parameters, exiting\n", __func__);
-		ret = -EINVAL;
+		return -EINVAL;
 	}
 
-	if (ret == 0) {
-
 	/* prepare the command frame */
 	frame->mrq = mrq;
 	frame->flags = FLAG_DO_ACK;
@@ -191,13 +189,13 @@ static int32_t tegra_bpmp_ipc_send_req_atomic(uint32_t mrq, void *p_out,
 
 	/* wait for slave to ack */
 	ret = tegra_bpmp_wait_for_slave_ack();
-		if (ret != 0) {
-			ERROR("failed waiting for the slave to ack\n");
+	if (ret < 0) {
+		ERROR("%s: wait for slave failed (%d)\n", __func__, ret);
+		return ret;
 	}
 
 	/* retrieve the response frame */
-		if ((size_in <= IVC_DATA_SZ_BYTES) && (p_in != NULL) &&
-		    (ret == 0)) {
+	if ((size_in <= IVC_DATA_SZ_BYTES) && (p_in != NULL)) {
 
 		f_in = tegra_bpmp_get_cur_in_frame();
 		if (f_in != NULL) {
@@ -207,12 +205,9 @@ static int32_t tegra_bpmp_ipc_send_req_atomic(uint32_t mrq, void *p_out,
 		}
 	}
 
-		if (ret == 0) {
 	ret = tegra_bpmp_free_master();
-			if (ret != 0) {
-				ERROR("Failed to free master\n");
-			}
-		}
+	if (ret < 0) {
+		ERROR("%s: free master failed (%d)\n", __func__, ret);
 	}
 
 	return ret;