Fix capitalization "CLang" -> "Clang"

Signed-off-by: Andrea Bolognani <abologna@redhat.com>

config.h

@@ -26,7 +26,7 @@
 #endif
 
 #ifndef __GNUC__
-# error "Libvirt requires GCC >= 4.8, or CLang"
+# error "Libvirt requires GCC >= 4.8, or Clang"
 #endif
 
 /*

docs/programming-languages.rst

@@ -11,7 +11,7 @@ some of the existing languages.
 The preferred languages at this time are:
 
 -  C - for the main libvirt codebase. Dialect supported by
-   GCC/CLang only.
+   GCC/Clang only.
 -  Python - for supporting build scripts / tools. Code must run
    with both version 2.7 and 3.x at this time.
 

meson.build

@@ -401,8 +401,8 @@ cc_flags += [
   # We do "bad" function casts all the time for event callbacks
   '-Wno-cast-function-type',
 
-  # CLang incorrectly complains about dup typedefs win gnu99 mode
-  # so use this CLang-specific arg to keep it quiet
+  # Clang incorrectly complains about dup typedefs win gnu99 mode
+  # so use this Clang-specific arg to keep it quiet
   '-Wno-typedef-redefinition',
 
   # Clang complains about casts in G_DEFINE_TYPE(...)

tests/qemusecuritymock.c

@@ -183,7 +183,7 @@ virFileGetXAttrQuiet(const char *path,
  * return value from virFileGetXAttrQuiet gets scrambled
  * if we mock virFileGetXAttrQuiet, returning -1 instead
  * of 0 despite succeeding. This happens on FreeBSD 11/12
- * hosts with CLang, and is suspected to be some kind of
+ * hosts with Clang, and is suspected to be some kind of
  * compiler optimization. By mocking this function too we
  * can workaround it.
  */