PV-shim: drop pv_console_rx()'s regs parameter

It's not needed anymore. This is in preparation of dropping the register
parameters from IRQ handler functions.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/guest/xen/xen.c

@@ -181,7 +181,7 @@ static void cf_check xen_evtchn_upcall(struct cpu_user_regs *regs)
             port += l1 * BITS_PER_LONG;
 
             if ( pv_console && port == pv_console_evtchn() )
-                pv_console_rx(regs);
+                pv_console_rx();
             else if ( pv_shim )
                 pv_shim_inject_evtchn(port);
         }

xen/drivers/char/xen_pv_console.c

@@ -94,7 +94,7 @@ evtchn_port_t pv_console_evtchn(void)
     return cons_evtchn;
 }
 
-size_t pv_console_rx(struct cpu_user_regs *regs)
+size_t pv_console_rx(void)
 {
     char c;
     XENCONS_RING_IDX cons, prod;

xen/include/xen/pv_console.h

@@ -9,7 +9,7 @@ void pv_console_init(void);
 void pv_console_set_rx_handler(serial_rx_fn fn);
 void pv_console_init_postirq(void);
 void pv_console_puts(const char *buf, size_t nr);
-size_t pv_console_rx(struct cpu_user_regs *regs);
+size_t pv_console_rx(void);
 evtchn_port_t pv_console_evtchn(void);
 
 #else
@@ -18,7 +18,7 @@ static inline void pv_console_init(void) {}
 static inline void pv_console_set_rx_handler(serial_rx_fn fn) { }
 static inline void pv_console_init_postirq(void) { }
 static inline void pv_console_puts(const char *buf, size_t nr) { }
-static inline size_t pv_console_rx(struct cpu_user_regs *regs) { return 0; }
+static inline size_t pv_console_rx(void) { return 0; }
 
 #endif /* !CONFIG_XEN_GUEST */
 #endif /* __XEN_PV_CONSOLE_H__ */