examples/unix/machine_bios.py: Fix typo.

Signed-off-by: Thomas <th.acker.0302@gmail.com>

examples/unix/machine_bios.py

@@ -1,5 +1,5 @@
 # This example shows how to access Video BIOS memory area via machine.mem
-# It requires root privilege and x86 legacy harfware (which has mentioned
+# It requires root privilege and x86 legacy hardware (which has mentioned
 # Video BIOS at all).
 # It is expected to print 0xaa55, which is a signature at the start of
 # Video BIOS.