UBUNTU: [debian] we already have a valid src_pkg_name

Signed-off-by: Andy Whitcroft <apw@canonical.com>

debian/rules.d/0-common-vars.mk

@@ -129,7 +129,6 @@ stampdir	:= $(CURDIR)/debian/stamps
 # are places that you'll find linux-image hard coded, but I guess thats OK since the
 # assumption that the binary package always starts with linux-image will never change.
 #
-src_pkg_name=linux
 bin_pkg_name=linux-image-$(abi_release)
 extra_pkg_name=linux-image-extra-$(abi_release)
 hdrs_pkg_name=linux-headers-$(abi_release)