microperl: fix MICROPERL_INSTALL_TARGET_CMDS

The MICROPERL_INSTALL_TARGET_CMDS used the following construct in a
for loop:

		[ -d $(@D)/lib/$$j ] && cp -af $(@D)/lib/$$j \
			$(TARGET_DIR)/$(MICROPERL_MODS_DIR) ; \
		[ -f $(@D)/lib/$$i ] && $(INSTALL) -m 0644 -D $(@D)/lib/$$i \
			$(TARGET_DIR)/$(MICROPERL_MODS_DIR)/$$i; \

The problem is that when at the last iteration, the second test (-f)
fails, then the whole loop ends with a non-zero error code, and makes
aborts the build. This happens for example if the last Perl modules in
the list is Time::Local, because such modules are taken care of by the
first condition (that copies a complete directory).

By moving to full if statements, we ensure that the return code is
zero even if the condition was false.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>