[Fix] add missing `local` (handle nonexisting /sbin/init a bit more cleanly)

nvm.sh

@@ -1871,6 +1871,7 @@ nvm_get_arch() {
   esac
 
   # If running a 64bit ARM kernel but a 32bit ARM userland, change ARCH to 32bit ARM (armv7l)
+  local L
   L=$(ls -dl /sbin/init 2>/dev/null) # if /sbin/init is 32bit executable
   if [ "$(uname)" = "Linux" ] && [ "${NVM_ARCH}" = arm64 ] && [ "$(od -An -t x1 -j 4 -N 1 "${L#*-> }")" = ' 01' ]; then
     NVM_ARCH=armv7l