ima: remove unnecessary call to ima_must_measure

The original ima_must_measure() function based its results on cached
iint information, which required an iint be allocated for all files.
Currently, an iint is allocated only for files in policy.  As a result,
for those files in policy, ima_must_measure() is now called twice: once
to determine if the inode is in the measurement policy and, the second
time, to determine if it needs to be measured/re-measured.

The second call to ima_must_measure() unnecessarily checks to see if
the file is in policy. As we already know the file is in policy, this
patch removes the second unnecessary call to ima_must_measure(), removes
the vestige iint parameter, and just checks the iint directly to determine
if the inode has been measured or needs to be measured/re-measured.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Eric Paris <eparis@redhat.com>
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index ac79032..08408bd 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -110,8 +110,7 @@
 };
 
 /* LIM API function definitions */
-int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
-		     int mask, int function);
+int ima_must_measure(struct inode *inode, int mask, int function);
 int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
 void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
 			   const unsigned char *filename);