libdpkg: Add missing <string.h> include

Warned-by: clang

debian/changelog

@@ -32,6 +32,7 @@ dpkg (1.18.11) UNRELEASED; urgency=medium
     standalone, by honoring SOURCE_DATE_EPOCH.
   * Portability:
     - Cast off_t variables to intmax_t when printing them with "%jd".
+    - Add missing <string.h> include in libdpkg.
   * Perl modules:
     - Obsolete Source-Version substvar in Dpkg::Substvars by emitting errors.
     - Rework keyring hooks in Dpkg::Vendor. Deprecate the keyrings hook, and

lib/dpkg/path-remove.c

@@ -26,6 +26,7 @@
 
 #include <assert.h>
 #include <errno.h>
+#include <string.h>
 #include <unistd.h>
 
 #include <dpkg/i18n.h>