- Fix delta time calculation in LinuxSemaphore::Wait.

SConstruct

Index: SConstruct
===================================================================
--- SConstruct	(revision 1730)
+++ SConstruct	(working copy)
@@ -108,7 +108,7 @@
     'os:linux': {
       'CCFLAGS':      ['-ansi'],
       'library:shared': {
-        'LIBS': ['pthread', 'rt']
+        'LIBS': ['pthread']
       }
     },
     'os:macos': {
@@ -224,7 +224,7 @@
 MKSNAPSHOT_EXTRA_FLAGS = {
   'gcc': {
     'os:linux': {
-      'LIBS': ['pthread', 'rt'],
+      'LIBS': ['pthread'],
     },
     'os:macos': {
       'LIBS': ['pthread'],
@@ -268,7 +268,7 @@
       'LIBPATH': [abspath('.')]
     },
     'os:linux': {
-      'LIBS':         ['pthread', 'rt'],
+      'LIBS':         ['pthread'],
     },
     'os:macos': {
       'LIBS':         ['pthread'],
@@ -307,7 +307,7 @@
       'CCFLAGS': ['-fno-rtti', '-fno-exceptions']
     },
     'os:linux': {
-      'LIBS':         ['pthread', 'rt'],
+      'LIBS':         ['pthread'],
     },
     'os:macos': {
       'LIBS':         ['pthread'],
@@ -387,7 +387,7 @@
       'LIBS': ['readline']
     },
     'os:linux': {
-      'LIBS': ['pthread', 'rt'],
+      'LIBS': ['pthread'],
     },
     'os:macos': {
       'LIBS': ['pthread'],