splice: HSM WIRE_HSMD_SIGN_SPLICE_TX capability not correctly checked

[ksedgwic]

Issue and Steps to Reproduce

lightningd/hsm_control.c: 171

	if (feature_offered(ld->our_features->bits[INIT_FEATURE],
			    WIRE_HSMD_SIGN_SPLICE_TX)
	    && !hsm_capable(ld, WIRE_HSMD_SIGN_SPLICE_TX)) {
		fatal("--experimental-splicing needs HSM capable of signing splices!");
	}

our_features->bits[INIT_FEATURE] should be compared to OPT_SPLICE and/or OPT_EXPERIMENTAL_SPLICE instead of the HSMD capabilities flag.

WIRE_HSMD_SIGN_SPLICE_TX is 29, I don't think any option uses that bit

getinfo output