Factor signal checks out of test scripts

Several test scripts now have some code to check for a program returning
a signal, and reporting a suitable failure.  This patch moves this
duplicated code into a helper function in tests.sh.  At the same time we
remove a bashism found in the current copies (using the non portablr $[ ]
construct for arithmetic).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

tests/dtc-checkfails.sh

@@ -17,10 +17,7 @@ trap "rm -f $LOG" 0
 verbose_run_log "$LOG" $VALGRIND "$DTC" -o /dev/null "$@"
 ret="$?"
 
-if [ "$ret" -gt 127 ]; then
-    signame=$(kill -l $[ret - 128])
-    FAIL "Killed by SIG$signame"
-fi
+FAIL_IF_SIGNAL $ret
 
 for c in $CHECKS; do
     if ! grep -E "^(ERROR)|(Warning) \($c\):" $LOG > /dev/null; then

tests/fdtget-runtest.sh

@@ -18,10 +18,7 @@ if [ "$ret" -ne 0 -a "$expect" = "ERR" ]; then
 	PASS
 fi
 
-if [ "$ret" -gt 127 ]; then
-    signame=$(kill -l $[ret - 128])
-    FAIL "Killed by SIG$signame"
-fi
+FAIL_IF_SIGNAL $ret
 
 diff $EXPECT $LOG
 ret="$?"

tests/fdtput-runtest.sh

@@ -29,19 +29,14 @@ ret="$?"
 if [ "$ret" -ne 0 -a "$expect" = "ERR" ]; then
 	PASS
 fi
-if [ "$ret" -gt 127 ]; then
-    signame=$(kill -l $[ret - 128])
-    FAIL "Killed by SIG$signame"
-fi
+
+FAIL_IF_SIGNAL $ret
 
 # Now fdtget to read the value
 verbose_run_log "$LOG" $VALGRIND "$DTGET" "$dtb" "$node" "$property" $flags
 ret="$?"
 
-if [ "$ret" -gt 127 ]; then
-    signame=$(kill -l $[ret - 128])
-    FAIL "Killed by SIG$signame"
-fi
+FAIL_IF_SIGNAL $ret
 
 diff $EXPECT $LOG
 ret="$?"

tests/tests.sh

@@ -10,6 +10,14 @@ FAIL () {
     exit 2
 }
 
+FAIL_IF_SIGNAL () {
+    ret="$1"
+    if [ "$ret" -gt 127 ]; then
+	signame=$(kill -l $((ret - 128)))
+	FAIL "Killed by SIG$signame"
+    fi
+}
+
 DTC=../dtc
 DTGET=../fdtget
 DTPUT=../fdtput