Revert "makepkg: calculate exact total file size"

This reverts commit b264fb9e9d.
With our "fix" of sleeping for BTRFS, we can go back to using `du` to
calculate total installed size.

configure.ac

@@ -282,6 +282,7 @@ esac
 
 AM_CONDITIONAL([CYGWIN], test "x$host_os_cygwin" = "xyes")
 AM_CONDITIONAL([DARWIN], test "x$host_os_darwin" = "xyes")
+AC_PATH_PROGS([DUPATH], [du], [du], [/usr/bin$PATH_SEPARATOR/bin] )
 AC_SUBST(SIZECMD)
 AC_SUBST(SEDINPLACE)
 AC_SUBST(STRIP_BINARIES)

scripts/Makefile.am

@@ -53,6 +53,7 @@ edit = sed \
 	-e 's|@BUILDSCRIPT[@]|$(BUILDSCRIPT)|g' \
 	-e 's|@SIZECMD[@]|$(SIZECMD)|g' \
 	-e 's|@SEDINPLACE[@]|$(SEDINPLACE)|g' \
+	-e 's|@DUPATH[@]|$(DUPATH)|g' \
 	-e 's|@SCRIPTNAME[@]|$@|g' \
 	-e 's|@configure_input[@]|Generated from $@.sh.in; do not edit by hand.|g'
 

scripts/makepkg.sh.in

@@ -1156,7 +1156,8 @@ write_pkginfo() {
 	else
 		local packager="Unknown Packager"
 	fi
-	local size="$(find . -print0 | xargs -0 @SIZECMD@ | awk '{ sum += $1 } END { print sum }')"
+	local size="$(@DUPATH@ -sk)"
+	size="$(( ${size%%[^0-9]*} * 1024 ))"
 
 	msg2 "$(gettext "Generating %s file...")" ".PKGINFO"
 	echo "# Generated by makepkg $myver"