Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/powerpc/oprofile/op_model_power4.c b/arch/powerpc/oprofile/op_model_power4.c
index 8077409..8ee51a2 100644
--- a/arch/powerpc/oprofile/op_model_power4.c
+++ b/arch/powerpc/oprofile/op_model_power4.c
@@ -207,7 +207,7 @@
 	unsigned long mmcra;
 	unsigned long slot;
 
-	/* Cant do much about it */
+	/* Can't do much about it */
 	if (!cur_cpu_spec->oprofile_mmcra_sihv)
 		return pc;