Rename some "kill" messages

Marlin/src/feature/mmu2/mmu2.cpp

Marlin/src/gcode/host/M16.cpp

Marlin/src/lcd/language/language_bg.h

Marlin/src/lcd/language/language_ca.h

Marlin/src/lcd/language/language_cz.h

Marlin/src/lcd/language/language_da.h

Marlin/src/lcd/language/language_de.h

Marlin/src/lcd/language/language_el.h

Marlin/src/lcd/language/language_el_gr.h

Marlin/src/lcd/language/language_en.h

Marlin/src/lcd/language/language_es.h

Marlin/src/lcd/language/language_eu.h

Marlin/src/lcd/language/language_fi.h

Marlin/src/lcd/language/language_fr.h

Marlin/src/lcd/language/language_gl.h

Marlin/src/lcd/language/language_hr.h

Marlin/src/lcd/language/language_it.h

Marlin/src/lcd/language/language_jp_kana.h

Marlin/src/lcd/language/language_ko_KR.h

Marlin/src/lcd/language/language_nl.h