Only exit at the end of a test, exit with the last value of $? that was not 0.

This way the entire regression test is looked at as a pass/fail, not just one
sub-test.

tools/regression/usr.bin/uudecode/regress.sh

@@ -7,13 +7,17 @@ if [ -z "$TESTDIR" ]; then
 fi
 cd $TESTDIR
 
+STATUS=0
+
 for test in traditional base64; do
   echo "Running test $test"
   uudecode -p < regress.$test.in | cmp regress.out -
   if [ $? -eq 0 ]; then
     echo "Test $test detected no regression, output matches."
   else
+    STATUS=$?
     echo "Test $test failed: regression detected.  See above."
-    exit 1
   fi
 done
+
+exit $STATUS

tools/regression/usr.bin/uuencode/regress.sh

@@ -7,6 +7,8 @@ if [ -z "$TESTDIR" ]; then
 fi
 cd $TESTDIR
 
+STATUS=0
+
 # Note that currently the uuencode(1) program provides no facility to
 # include the file mode explicitly based on an argument passed to it,
 # so the regress.in file must be mode 644, or the test will say that,
@@ -25,7 +27,9 @@ for test in traditional base64; do
   if [ $? -eq 0 ]; then
     echo "Test $test detected no regression, output matches."
   else
+    STATUS=$?
     echo "Test $test failed: regression detected.  See above."
-    exit 1
   fi
 done
+
+exit $STATUS

tools/regression/usr.bin/xargs/regress.sh

@@ -7,6 +7,8 @@ if [ -z "$TESTDIR" ]; then
 fi
 cd $TESTDIR
 
+STATUS=0
+
 for test in normal I J L; do
   echo "Running test $test"
   case "$test" in
@@ -26,7 +28,9 @@ for test in normal I J L; do
   if [ $? -eq 0 ]; then
     echo "Test $test detected no regression, output matches."
   else
+    STATUS=$?
     echo "Test $test failed: regression detected.  See above."
-    exit 1
   fi
 done
+
+exit $STATUS