Fixes:
rigctld.c:1233:5: warning: implicit declaration of function ‘mutext_rigctld’; did you mean ‘mutex_rigctld’? [-Wimplicit-function-declaration]
rigctltcp.c:1217:5: warning: implicit declaration of function ‘mutext_rigctld’; did you mean ‘mutex_rigctld’? [-Wimplicit-function-declaration]