configure.ac: Add missing quotes to AC_CHECK_SIZEOF calls

ChangeLog

@@ -1,3 +1,7 @@
+2008-01-18  Guillem Jover  <guillem@debian.org>
+
+	* configure.ac (AC_CHECK_SIZEOF): Quote parameters.
+
 2008-01-18  Guillem Jover  <guillem@debian.org>
 
 	* THANKS: Add all the people that have contributed until now.

configure.ac

@@ -85,8 +85,8 @@ AC_TYPE_MODE_T
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 DPKG_TYPE_PTRDIFF_T
-AC_CHECK_SIZEOF(unsigned int)
-AC_CHECK_SIZEOF(unsigned long)
+AC_CHECK_SIZEOF([unsigned int])
+AC_CHECK_SIZEOF([unsigned long])
 DPKG_DECL_SYS_SIGLIST
 DPKG_C_ATTRIBUTE