package/usb_modeswitch: avoid overriding variables

Overriding variables in packages recipes is an error-prone practice.

Current behavior of installing either only as a script or only as a
binary is intended, as describe in the commit log of "d3e4db4e34
usb_modeswitch: bump to version 1.2.6" from 2013.

Rewrite the code to keep the same behavior while replacing variable
override [1] by conditional assignments [2].

[1]
VAR = ...
if ...
VAR = ...

[2]
if ...
VAR = ...
else
VAR = ...

Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit e25040d31a8d50c3c523f78f43ba1f557269b3bb)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/usb_modeswitch/usb_modeswitch.mk

@@ -13,13 +13,13 @@ USB_MODESWITCH_LICENSE_FILES = COPYING
 # Package does not build in parallel due to improper make rules
 USB_MODESWITCH_MAKE = $(MAKE1)
 
-USB_MODESWITCH_BUILD_TARGETS = static
-USB_MODESWITCH_INSTALL_TARGETS = install-static
-
 ifeq ($(BR2_PACKAGE_TCL)$(BR2_PACKAGE_TCL_SHLIB_ONLY),y)
 USB_MODESWITCH_DEPENDENCIES += tcl
 USB_MODESWITCH_BUILD_TARGETS = script
 USB_MODESWITCH_INSTALL_TARGETS = install-script
+else
+USB_MODESWITCH_BUILD_TARGETS = static
+USB_MODESWITCH_INSTALL_TARGETS = install-static
 endif
 
 # build system of embedded jimtcl doesn't use autotools, but does use