recipetool: Fix circular reference in SRC_URI

When creating a new recipe.bb file for a binary, don't use BP which
includes the version information, instead use BPN which is just the
name base Package Name.

Since PB is not specified, it takes the default:
PV = "1.0+git${SRCPV}"

But SRCPV is defined in terms of the SRC_URI, which leads to infinite
recursion (traceback below). Here are the pertinent variables which
cause the recursion:

SRC_URI = "git://github.com/lvc/abi-dumper;protocol=https;subdir=${BP}

"
BP = "${BPN}-${PV}"
PV = "1.0+git${SRCPV}"
SRCPV = "${@bb.fetch2.get_srcrev(d)}"

def get_srcrev(d, method_name='sortable_revision'):
    # ... trimmed
    scms = []
    fetcher = Fetch(d.getVar('SRC_URI').split(), d)
    # ... trimmed

[YOCTO #14040]

Signed-off-by: Saul Wold <saul.wold@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>