logging: Use __BASE_FILE__ instead of __FILE__

Apparently __FILE__ expands to nasty '../../..' paths when BUILDDIR !=
SRCDIR.  This in turn leads to ugly log lines like:

<0000> ../../../../osmo-bts/src/common/rsl.c:1642 (bts=0,trx=0,ts=0,ss=0) Handing RLL msg UNIT_DATA_IND from LAPDm to MEAS REP

Where we certainly wouldn't want the "../../../../osmo-bts" part.

Change-Id: If6d2de33c3b6bb2943954bbd81eff261dc279d58
Reviewed-on: https://gerrit.osmocom.org/38
Tested-by: Jenkins Builder
Reviewed-by: Harald Welte <laforge@gnumonks.org>
diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 89d3f94..3da9d33 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -27,13 +27,13 @@
 #define DEBUGP(ss, fmt, args...) \
 	do { \
 		if (log_check_level(ss, LOGL_DEBUG)) \
-			logp(ss, __FILE__, __LINE__, 0, fmt, ## args); \
+			logp(ss, __BASE_FILE__, __LINE__, 0, fmt, ## args); \
 	} while(0)
 
 #define DEBUGPC(ss, fmt, args...) \
 	do { \
 		if (log_check_level(ss, LOGL_DEBUG)) \
-			logp(ss, __FILE__, __LINE__, 1, fmt, ## args); \
+			logp(ss, __BASE_FILE__, __LINE__, 1, fmt, ## args); \
 	} while(0)
 
 #else
@@ -56,7 +56,7 @@
 #define LOGP(ss, level, fmt, args...) \
 	do { \
 		if (log_check_level(ss, level)) \
-			logp2(ss, level, __FILE__, __LINE__, 0, fmt, ##args); \
+			logp2(ss, level, __BASE_FILE__, __LINE__, 0, fmt, ##args); \
 	} while(0)
 
 /*! \brief Continue a log message through the Osmocom logging framework
@@ -68,7 +68,7 @@
 #define LOGPC(ss, level, fmt, args...) \
 	do { \
 		if (log_check_level(ss, level)) \
-			logp2(ss, level, __FILE__, __LINE__, 1, fmt, ##args); \
+			logp2(ss, level, __BASE_FILE__, __LINE__, 1, fmt, ##args); \
 	} while(0)
 
 /*! \brief different log levels */