Fix abbr return status

This was supposed to act like `type -q` or `command -q`, in that it
returns 0 if at least 1 exists.

But because it used the wrong variable it didn't.

Fixes #8431.

share/functions/abbr.fish

@@ -59,7 +59,7 @@ function abbr --description "Manage abbreviations"
         # We return 0 if any arg exists, whereas `set -q` returns the number of undefined arguments.
         # But we should be consistent with `type -q` and `command -q`.
         for var in $escaped
-            set -q $escaped; and return 0
+            set -q $var; and return 0
         end
         return 1
     else

tests/checks/abbr.fish

@@ -94,3 +94,15 @@ abbr --add --global __abbr14 bbbbbbbbbbbbb
 abbr --erase __abbr13 __abbr14
 abbr | grep __abbr13
 abbr | grep __abbr14
+
+abbr -q banana
+echo $status
+# CHECK: 1
+
+abbr -q __abbr8 banana
+echo $status
+# CHECK: 0
+
+abbr -q banana __abbr8 foobar
+echo $status
+# CHECK: 0