The value of the RM variable in make is 'rm -f' [0], thus the additional
-f is redundant. Avoid it on the docs to avoid developers taking it as a
good example to follow.
[0] https://www.gnu.org/software/make/manual/make.html#index-RM
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>