fix bad static_assert

src/rp2_common/hardware_powman/include/hardware/powman.h

diff --git a/src/rp2_common/hardware_powman/include/hardware/powman.h b/src/rp2_common/hardware_powman/include/hardware/powman.h
index 48fc471..ec88ef9 100644
--- a/src/rp2_common/hardware_powman/include/hardware/powman.h
+++ b/src/rp2_common/hardware_powman/include/hardware/powman.h
@@ -223,7 +223,7 @@
 }
 
 static inline pstate_bitset_t *pstate_bitset_from_powman_power_state(pstate_bitset_t *domains, powman_power_state pstate) {
-    static_assert(sizeof(powman_power_state) <= sizeof(uint32_t));
+    static_assert(sizeof(powman_power_state) <= sizeof(uint32_t), "");
     fixed_bitset_write_word(&domains->bitset, 0, pstate);
     return domains;
 }