mwrap-perl: use grep and fix regexp

There's no need to pay O(n) cost to create a short-lived
hash table and the original regexp was obviously wrong :x

1 files changed, 2 insertions, 3 deletions

diff --git a/script/mwrap-perl b/script/mwrap-perl
index 4350fcc..78e71e3 100644
--- a/script/mwrap-perl
+++ b/script/mwrap-perl
@@ -8,10 +8,9 @@ defined($so) or die 'Mwrap.so not loaded';
 my $cur = $ENV{LD_PRELOAD};
 if (defined $cur) {
         my @cur = split(/[: \t]+/, $cur);
-        my %cur = map { $_ => 1 } @cur;
-        if (!$cur{$so}) {
+        if (!grep(/\A\Q$so\E\z/, @cur)) {
                 # drop old redundant versions
-                my @keep = grep(!m!/Mwrap\.so\$!, @cur);
+                my @keep = grep(!m!/Mwrap\.so$!, @cur);
                 $ENV{LD_PRELOAD} = join(':', $so, @keep);
         }
 } else {