tests: use "Exit $fail", not (exit $fail); exit $fail

* tests/test-lib.sh (Exit): New function by Ralf Wildenhues in automake
http://git.sv.gnu.org/gitweb/?p=automake.git;a=commitdiff;h=20594c08f63
* tests/**: Convert all uses:

This restrictive change converted the vast majority:

  git grep -l '^(exit \$fail); exit \$fail$' \
    | xargs perl -pi -e 's/'^\(exit \$fail\); exit \$fail$/Exit \$fail/'

And this did the rest, plus a few undesirable ones, so I manually
backed out the changes to ChangeLog-* and build-aux/check.mk:

  git grep -l -E '\(exit [^)]+\); exit ' \
    | xargs perl -pi -e 's/\(exit (.+?)\); exit \1/Exit $1/'

tests/mkdir/p-1

@@ -27,4 +27,4 @@ fail=0
 mkdir --parents "`pwd`/t" || fail=1
 test -d t || fail=1
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/p-2

@@ -27,4 +27,4 @@ fail=0
 mkdir --parents "`pwd`/t/u" || fail=1
 test -d t/u || fail=1
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/p-3

@@ -52,4 +52,4 @@ b=`ls "$p/a" | tr -d '\n'`
 # With coreutils-5.3.0, this would fail with $b=bu.
 test "x$b" = xb || fail=1
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/p-slashdot

@@ -31,4 +31,4 @@ test -d d1 || fail=1
 mkdir -p d2/.. || fail=1
 test -d d2 || fail=1
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/p-thru-slink

@@ -29,4 +29,4 @@ fail=0
 mkdir -p slink/x || fail=1
 test -d x || fail=1
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/p-v

@@ -34,4 +34,4 @@ mkdir: created directory `foo/a/b/c'
 mkdir: created directory `foo/a/b/c/d'
 EOF
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/parents

@@ -53,4 +53,4 @@ p=`ls -ld a/b/c|cut -b-10`; case $p in drwx------);; *) fail=1;; esac
 # `d's perms are determined by the -m argument.
 p=`ls -ld a/b/c/d|cut -b-10`; case $p in $d_mode_str);; *) fail=1;; esac
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/perm

@@ -85,4 +85,4 @@ for p in empty -p; do
   done
 done
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/selinux

@@ -56,4 +56,4 @@ for cmd_w_arg in 'mkdir dir' 'mknod b p' 'mkfifo f'; do
   compare out exp || fail=1
 done
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/special-1

@@ -52,4 +52,4 @@ case "$mode" in
   *) fail=1 ;;
 esac
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/t-slash

@@ -33,4 +33,4 @@ test -d dir || fail=1
 mkdir d2/ || fail=1
 test -d d2 || fail=1
 
-(exit $fail); exit $fail
+Exit $fail

tests/mkdir/writable-under-readonly

@@ -54,4 +54,4 @@ mkdir -p mnt-ro/rw/sub || fail=1
 umount /tmp/2
 umount /tmp/1
 
-(exit $fail); exit $fail
+Exit $fail