ref(core/hypercall): rename first argument

This commit renames the first argument of the hypercall to make
the code independent of the specific hypercall type.

Signed-off-by: João Peixoto <[email protected]>

Author: joaopeixoto13

src/core/hypercall.c

@@ -12,13 +12,13 @@ long int hypercall(unsigned long id)
 {
     long int ret = -HC_E_INVAL_ID;
 
-    unsigned long ipc_id = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(0));
+    unsigned long arg0 = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(0));
     unsigned long arg1 = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(1));
     unsigned long arg2 = vcpu_readreg(cpu()->vcpu, HYPCALL_ARG_REG(2));
 
     switch (id) {
         case HC_IPC:
-            ret = ipc_hypercall(ipc_id, arg1, arg2);
+            ret = ipc_hypercall(arg0, arg1, arg2);
             break;
         default:
             WARNING("Unknown hypercall id %d", id);