Removing this ifdef/endif pair yields a "defined but unused warning"
for CONFIG_CMD_SAVEENV=n, but that vanishes if we use the ENV_SAVE_PTR
macro instead. This gives slightly better compile testing, and
moreover, it's possible to have
CONFIG_CMD_SAVEENV=n
CONFIG_SPL_SAVEENV=y
SPL_ENV_IS_IN_EXT4=y
in which case env_ext4_save would erroneously not be compiled in.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>