x86/fault: Make fault messages more succinct

So we are going to be staring at those in the next years, let's make
them more succinct. In particular:

 - change "address = " to "address: "

 - "-privileged" reads funny. It should be simply "kernel" or "user"

 - "from kernel code" reads funny too. "kernel mode" or "user mode" is
   more natural.

An actual example says more than 1000 words, of course:

  [    0.248370] BUG: kernel NULL pointer dereference, address: 00000000000005b8
  [    0.249120] #PF: supervisor write access in kernel mode
  [    0.249717] #PF: error_code(0x0002) - not-present page
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@linux.intel.com
Cc: luto@kernel.org
Cc: riel@surriel.com
Cc: sean.j.christopherson@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20190421183524.GC6048@zn.tnicSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/mm/fault.c

@@ -630,13 +630,13 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
 	}
 
 	if (address < PAGE_SIZE && !user_mode(regs))
-		pr_alert("BUG: kernel NULL pointer dereference, address = %px\n",
+		pr_alert("BUG: kernel NULL pointer dereference, address: %px\n",
 			(void *)address);
 	else
-		pr_alert("BUG: unable to handle page fault for address = %px\n",
+		pr_alert("BUG: unable to handle page fault for address: %px\n",
 			(void *)address);
 
-	pr_alert("#PF: %s-privileged %s from %s code\n",
+	pr_alert("#PF: %s %s in %s mode\n",
 		 (error_code & X86_PF_USER)  ? "user" : "supervisor",
 		 (error_code & X86_PF_INSTR) ? "instruction fetch" :
 		 (error_code & X86_PF_WRITE) ? "write access" :