Capture stdout of `cat` commands in case they die

Change-Id: Ia1d152cf2c2c2defcb420037c69823ecefe7ff82
diff --git a/nexus-non-interactive-test.sh b/nexus-non-interactive-test.sh
index c60b67c..4f7ac01 100755
--- a/nexus-non-interactive-test.sh
+++ b/nexus-non-interactive-test.sh
@@ -75,9 +75,9 @@
 stty --file="/dev/Nexus-FTDI-${NEXUS_ID}-MCU-UART" 115200
 
 # Starting logging the UARTs
-cat "/dev/Nexus-FTDI-${NEXUS_ID}-FPGA-UART" > uart.sc.log &
+cat "/dev/Nexus-FTDI-${NEXUS_ID}-FPGA-UART" > uart.sc.log 2> uart.sc.err &
 SC_UART_PID=$!
-cat "/dev/Nexus-CP210-FPGA-UART-${NEXUS_ID}" > uart.smc.log &
+cat "/dev/Nexus-CP210-FPGA-UART-${NEXUS_ID}" > uart.smc.log 2> uart.smc.err &
 SMC_UART_PID=$!
 
 # Logging cleanup for when the script exits
@@ -125,7 +125,9 @@
     done' || echo "Time out waiting for PASS! or FAIL! log"
 
 cat -n uart.sc.log
+cat -n uart.sc.err
 cat -n uart.smc.log
+cat -n uart.smc.err
 
 grep -q "PASS!" uart.sc.log uart.smc.log
 exit $?