x86/resctrl: Use rdt_last_cmd_puts() where possible

The last_cmd_status sequence buffer contains user-visible messages
(accessed via /sys/fs/resctrl/info/last_cmd_status) that detail any
errors encountered while interacting with the resctrl filesystem.

rdt_last_cmd_printf() and rdt_last_cmd_puts() are the two calls
available to respectively print a string with format specifiers or a
simple one (which contains no format specifiers) to the last_cmd_status
buffer.

A few occurrences exist where rdt_last_cmd_printf() is used to print
a simple string. Doing so does not result in incorrect result or
incorrect behavior, but rdt_last_cmd_puts() is the function intended to
be used in these cases, as it is faster and it doesn't need to do the
vsnprintf() formatting.

Fix these occurrences to use rdt_last_cmd_puts() instead. While doing
so, fix two typos that were recently introduced into two of these simple
strings.

 [ bp: massage commit message and correct typos. ]

Fixes: 723f1a0dd8 ("x86/resctrl: Fixup the user-visible strings")
Fixes: e0bdfe8e36 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Fixes: 9ab9aa15c3 ("x86/intel_rdt: Ensure requested schemata respects mode")
Fixes: d48d7a57f7 ("x86/intel_rdt: Introduce resource group's mode resctrl file")
Fixes: dfe9674b04 ("x86/intel_rdt: Enable entering of pseudo-locksetup mode")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: babu.moger@amd.com
Cc: jithu.joseph@intel.com
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/f48e46a016d6a5c79f13de8faeca382052189e2e.1543346009.git.reinette.chatre@intel.com

arch/x86/kernel/cpu/resctrl/rdtgroup.c

@@ -1206,7 +1206,7 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
 		goto out;
 
 	if (mode == RDT_MODE_PSEUDO_LOCKED) {
-		rdt_last_cmd_printf("Cannot change pseudo-locked group\n");
+		rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
 		ret = -EINVAL;
 		goto out;
 	}
@@ -1235,7 +1235,7 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
 			goto out;
 		rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
 	} else {
-		rdt_last_cmd_printf("Unknown orunsupported mode\n");
+		rdt_last_cmd_puts("Unknown or unsupported mode\n");
 		ret = -EINVAL;
 	}