*: more --help tweaking

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

miscutils/i2c_tools.c

@@ -1394,7 +1394,7 @@ static void check_i2c_func(int fd)
 }
 
 //usage:#define i2ctransfer_trivial_usage
-//usage:       "[-fay] I2CBUS {rLENGTH[@ADDR] | wLENGTH[@ADDR] DATA...}..."
+//usage:       "[-fay] I2CBUS { rLENGTH[@ADDR] | wLENGTH[@ADDR] DATA...}..."
 //usage:#define i2ctransfer_full_usage "\n\n"
 //usage:       "Read/write I2C data in one transfer"
 //usage:     "\n"

miscutils/mt.c

@@ -19,7 +19,7 @@
 //usage:#define mt_full_usage "\n\n"
 //usage:       "Control magnetic tape drive operation\n"
 //usage:       "\n"
-//usage:       "Available Opcodes:\n"
+//usage:       "Opcodes:\n"
 //usage:       "\n"
 //usage:       "bsf bsfm bsr bss datacompression drvbuffer eof eom erase\n"
 //usage:       "fsf fsfm fsr fss load lock mkpart nop offline ras1 ras2\n"