actions.c: handle 61 -Wextra-semi-stmt warnings from clang
Wrap XCALC_PRE_OP
macro definition in do {...} while (0)
to
clear up warnings from clang 13 of the form:
actions.c:161:23: warning: empty expression statement has no effect;
remove unnecessary ';' to silence this warning [-Wextra-semi-stmt]
XCALC_PRE_OP(kADD);
^
Signed-off-by: Alan Coopersmith