fix(scripts/termux_step_install_license): fix logic error

Move counter advance to the end of the while loop.
This fixes a logic error where the counter wouldn't advance
if the first license was "generic", and the second one was
author specific. This would cause `cp` to attempt to copy
through the dangling symlink to the generic license
in `termux-licenses` which fails and dies.

scripts/build/termux_step_install_license.sh

@@ -60,29 +60,27 @@ termux_step_install_license() {
 						else
 							cp -f "${TERMUX_PKG_SRCDIR}/$FILE" "${TERMUX_PREFIX}/share/doc/${TERMUX_PKG_NAME}/copyright"
 						fi
-						# since this is a post-increment, (( 0 )) would be falsey
-						# thus `set -e` would kill the script on the first iteration
-						# using `true` prevents this
-						: $(( COUNTER++ ))
 					}
 				done
 				;;
 				# For the rest we can use a link to the generic license file
 				*) [[ -f "$TERMUX_SCRIPTDIR/packages/termux-licenses/LICENSES/${LICENSE}.txt" ]] && {
 						# the link target depends on the libc being used
-						if [[ "$TERMUX_PACKAGE_LIBRARY" == 'bionic' ]]; then
-							TO_LICENSE="../../LICENSES/${LICENSE}.txt"
-						elif [[ "$TERMUX_PACKAGE_LIBRARY" == 'glibc' ]]; then
-							TO_LICENSE="../../../../share/LICENSES/${LICENSE}.txt"
-						fi
+						case "$TERMUX_PACKAGE_LIBRARY" in
+							'bionic') TO_LICENSE="../../LICENSES/${LICENSE}.txt";;
+							'glibc')  TO_LICENSE="../../../../share/LICENSES/${LICENSE}.txt";;
+							*)        termux_error_exit "'$TERMUX_PACKAGE_LIBRARY' is not a supported libc";;
+
+						esac
 						if (( COUNTER )); then
-							ln -sf "$TO_LICENSE" "$TERMUX_PREFIX/share/doc/$TERMUX_PKG_NAME/copyright.$((COUNTER++))"
+							ln -sf "$TO_LICENSE" "$TERMUX_PREFIX/share/doc/$TERMUX_PKG_NAME/copyright.${COUNTER}"
 						else
 							ln -sf "$TO_LICENSE" "$TERMUX_PREFIX/share/doc/$TERMUX_PKG_NAME/copyright"
 						fi
 					}
 				;;
 			esac
+			(( ++COUNTER ))
 		done <<< "${TERMUX_PKG_LICENSE//,/$'\n'}"
 		local license_files
 		license_files="$(find -L "$TERMUX_PREFIX/share/doc/$TERMUX_PKG_NAME" -maxdepth 1 \( -type f -o -type l \) -name "copyright*")"