Look for 'vfio_user' in SPDK_LIB_FILES to determine whether the target application actually needs to be rebuilt. Fixes issue #1930. Signed-off-by: Jim Harris <james.r.harris@intel.com> Change-Id: If3f699c91972e20dc4520e25c655ed11f6843be0 Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/7826 Reviewed-by: Changpeng Liu <changpeng.liu@intel.com> Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com> Reviewed-by: <dongx.yi@intel.com> Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>