Fix typo

Corresponding to flashrom svn r426 and coreboot v2 svn r4089.
Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>

flashrom.8

 .TH FLASHROM 8 "January 5, 2009"
 .SH NAME
-flashrom \- utility for reading, writing, and erasong BIOS/ROM/flash chips
+flashrom \- utility for reading, writing, and erasing BIOS/ROM/flash chips
 .SH SYNOPSIS
 .B flashrom \fR[\fB\-rwvEVfLhR\fR] [\fB\-c\fR chipname] [\fB\-s\fR exclude_start] [\fB\-e\fR exclude_end]
          [\fB-m\fR vendor:part] [\fB-l\fR file.layout] [\fB-i\fR image_name] [file]