Remove trailing white space with:

for f in *.{h,c}; do sed -i .sed 's/[[:blank:]]*$//' $f; done
(Thanks to Nicolás Wolovick)

ioapic.c

@@ -13,7 +13,7 @@
 #define REG_TABLE  0x10  // Redirection table base
 
 // The redirection table starts at REG_TABLE and uses
-// two registers to configure each interrupt.  
+// two registers to configure each interrupt.
 // The first (low) register in a pair contains configuration bits.
 // The second (high) register contains a bitmask telling which
 // CPUs can serve that interrupt.