Fix gRPC Core API void function definition

include/grpc/grpc_security.h

@@ -185,7 +185,7 @@ GRPCAPI grpc_call_credentials *grpc_composite_call_credentials_create(
 GRPCAPI grpc_call_credentials *grpc_google_compute_engine_credentials_create(
     void *reserved);
 
-GRPCAPI gpr_timespec grpc_max_auth_token_lifetime();
+GRPCAPI gpr_timespec grpc_max_auth_token_lifetime(void);
 
 /** Creates a JWT credentials object. May return NULL if the input is invalid.
    - json_key is the JSON key string containing the client's private key.

include/grpc/support/alloc.h

@@ -58,7 +58,7 @@ GPRAPI void gpr_free_aligned(void *ptr);
 GPRAPI void gpr_set_allocation_functions(gpr_allocation_functions functions);
 
 /** Return the family of allocation functions currently in effect. */
-GPRAPI gpr_allocation_functions gpr_get_allocation_functions();
+GPRAPI gpr_allocation_functions gpr_get_allocation_functions(void);
 
 #ifdef __cplusplus
 }

include/grpc/support/log.h

@@ -68,7 +68,7 @@ GPRAPI void gpr_log_message(const char *file, int line,
 /** Set global log verbosity */
 GPRAPI void gpr_set_log_verbosity(gpr_log_severity min_severity_to_print);
 
-GPRAPI void gpr_log_verbosity_init();
+GPRAPI void gpr_log_verbosity_init(void);
 
 /** Log overrides: applications can use this API to intercept logging calls
    and use their own implementations */