efi_loader: fix function comments in efi_boottime.c

scripts/kernel-doc pointed out some errors in the function comments in
efi_boottime.c.

Add missing and remove superfluous parameter descriptions.
Escape * in a function description.
Add empty lines for readability.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
1 file changed