Fix function declaration

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 071ac61..2fcb5c1 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4608,7 +4608,7 @@
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
 static int ecp_mod_p192k1(mbedtls_mpi *);
-MBEDTLS_TEST_HOOKS
+MBEDTLS_STATIC_TESTABLE
 int mbedtls_ecp_mod_p192k1(mbedtls_mpi *);
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)