debian: Fix typos in changelog

Reported-by: Niels Thykier <niels@thykier.net> (variable typo)

debian/changelog

@@ -112,7 +112,7 @@ dpkg (1.18.0) unstable; urgency=low
       clarify what whitespace really maps to, we should really match the GnuPG
       implementation anyway, as that's what we use to verify the signatures.
       Reported by Jann Horn <jann@thejh.net>. Fixes CVE-2015-0840.
-    - Pass PATCH_GET environment varialbe instead of -g0 to the patch command
+    - Pass PATCH_GET environment variable instead of -g0 to the patch command
       in Dpkg::Source::Patch. This allows using non-GNU patch programs, like
       FreeBSD's patch.
     - Accept an %opts argument for the Dpkg::Control::Info constructor, and
@@ -226,7 +226,7 @@ dpkg (1.18.0) unstable; urgency=low
     - Add missing preposition in Dpkg::Source::Patch error message.
     - Improve available state sorting order strings in dselect panel.
     - Say “changelog-file” instead of “changelogfile” in --help output.
-    - Say “command“ instead of “action“ for dselect.
+    - Say “command” instead of “action” for dselect.
     - Improve commands listing in «dselect --help» output, by printing them
       before options and listing them one on each line with a description.
     - Improve dselect color-spec --help output.