make find_pid_by_name look at /proc/PID/exe too

function                                             old     new   delta
procps_scan                                         1642    1709     +67
find_pid_by_name                                     193     223     +30
free_procps_scan                                      29      37      +8

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/include/libbb.h b/include/libbb.h
index c7b4de1..51ac69e 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1280,6 +1280,7 @@
 /* Fields are set to 0/NULL if failed to determine (or not requested) */
 	uint16_t argv_len;
 	char *argv0;
+	char *exe;
 	IF_SELINUX(char *context;)
 	/* Everything below must contain no ptrs to malloc'ed data:
 	 * it is memset(0) for each process in procps_scan() */
@@ -1327,7 +1328,7 @@
 	PSSCAN_COMM     = 1 << 5,
 	/* PSSCAN_CMD      = 1 << 6, - use read_cmdline instead */
 	PSSCAN_ARGV0    = 1 << 7,
-	/* PSSCAN_EXE      = 1 << 8, - not implemented */
+	PSSCAN_EXE      = 1 << 8,
 	PSSCAN_STATE    = 1 << 9,
 	PSSCAN_VSZ      = 1 << 10,
 	PSSCAN_RSS      = 1 << 11,