tcl_commands/all.tcl: set_log FP_ENDCAP_CELL only if defined
tcl_commands/all.tcl: set_log FP_ENDCAP_CELL only if defined

Some standard cell libraries have no end cap cell (like
sky130_osu_sc_t18)

efabless/openlane,efabless/openlane,efabless/openlane,efabless/openlane