Send stderr of pkgconf to /dev/null rather than printing the following
error text while parsing the spec file:
Package krb5 was not found in the pkg-config search path.
Perhaps you should add the directory containing `krb5.pc'
to the PKG_CONFIG_PATH environment variable
Package 'krb5', required by 'virtual:world', not found
`BuildRequires: pkgconfig(krb5)` ensures this won't happen when running
a real build. It simply avoids 4 lines of needless error output when
running something like `fedpkg prep`.
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Todd Zullinger