Added quoting to usb_producer key to preserve double quotes.

See #1422.

Author: cmaglie

hardware/arduino/avr/platform.txt

@@ -91,4 +91,4 @@ tools.avrdude.bootloader.pattern="{cmd.path}" "-C{config.path}" {bootloader.verb
 # Default blank usb manufacturer will be filled it at compile time
 # - from numeric vendor ID, set to Unknown otherwise
 build.usb_manufacturer=
-build.usb_flags=-DUSB_VID={build.vid} -DUSB_PID={build.pid} -DUSB_MANUFACTURER={build.usb_manufacturer} '-DUSB_PRODUCT={build.usb_product}'
+build.usb_flags=-DUSB_VID={build.vid} -DUSB_PID={build.pid} '-DUSB_MANUFACTURER={build.usb_manufacturer}' '-DUSB_PRODUCT={build.usb_product}'

hardware/arduino/sam/platform.txt

@@ -35,7 +35,7 @@ compiler.libsam.c.flags="-I{build.system.path}/libsam" "-I{build.system.path}/CM
 
 # USB Flags
 # ---------
-build.usb_flags=-DUSB_VID={build.vid} -DUSB_PID={build.pid} -DUSBCON -DUSB_MANUFACTURER={build.usb_manufacturer} '-DUSB_PRODUCT={build.usb_product}'
+build.usb_flags=-DUSB_VID={build.vid} -DUSB_PID={build.pid} -DUSBCON '-DUSB_MANUFACTURER={build.usb_manufacturer}' '-DUSB_PRODUCT={build.usb_product}'
 
 # Default usb manufacturer will be replaced at compile time using
 # numeric vendor ID if available or by board's specific value.