[shellcheck] fix silly shellcheck complaint
diff --git a/nvm.sh b/nvm.sh
index 4646dd9..2f59708 100644
--- a/nvm.sh
+++ b/nvm.sh
@@ -2339,7 +2339,7 @@
   # npm first looks at $PREFIX (case-sensitive)
   # we do not bother to test the value here; if this env var is set, unset it to continue.
   # however, `npm exec` in npm v7.2+ sets $PREFIX; if set, inherit it
-  if [ -n "${PREFIX-}" ] && [ "$(nvm_version_path $(node -v))" != "${PREFIX}" ]; then
+  if [ -n "${PREFIX-}" ] && [ "$(nvm_version_path "$(node -v)")" != "${PREFIX}" ]; then
     nvm deactivate >/dev/null 2>&1
     nvm_err "nvm is not compatible with the \"PREFIX\" environment variable: currently set to \"${PREFIX}\""
     nvm_err 'Run `unset PREFIX` to unset it.'