Avoid compiling prof.c with -pg flags

ee/libprofglue/src/mcount.S

@@ -16,30 +16,12 @@ _mcount:
         sd   $a2, 32($sp)
         sd   $a3, 40($sp)
 
-# Make sure we're not recursively called when compiling __mcount()
-# With -pg
-        la   $a0, _busy
-        lw   $a1, 0($a0)
-        bnez $a1, done
-        nop
-
-# Mark busy
-        li   $a1, 1
-        sw   $a1, 0($a0)
-
 # Call internal C handler
         move $a0, $at
         move $a1, $ra
         jal  __mcount
         nop
 
-# Unmark busy
-        la   $a0, _busy
-        li   $a1, 0
-        sw   $a1, 0($a0)
-
-done:
-
 # Restore registers
         ld   $ra, 0($sp)
         ld   $at, 8($sp)
@@ -51,9 +33,6 @@ done:
         jr   $ra
         move $ra, $at            # restore caller's ra
 
-_busy:
-        .space 4
-
     .end _mcount
 
     .set reorder

ee/libprofglue/src/prof.c

@@ -192,6 +192,7 @@ void __gprof_cleanup()
     beginning of each compiled routine, which eventually brings the
     control to here.
 */
+__attribute__((__no_instrument_function__, __no_profile_instrument_function__))
 void __mcount(unsigned int frompc, unsigned int selfpc)
 {
     int e;